Under a blue sky, about 15 Orthodox priests surrounded Pope John Paul II to sing after the Gospel of the Easter Sunday Mass. Christos (Christ) and Pascha (Passover) were the only two Greek words I could recognize from their melodious Greek Easter hymn.

The reason for such an unusual choir? This year both Western and Eastern churches celebrated Easter on the same day, April 11. “A happy coincidence,” John Paul remarked.

In the second century, a sharp controversy arose within the Church about when to celebrate the Christian Passover. The churches in Asia Minor, Syria and Cilicia celebrated it on the anniversary of Christ's death, the first full moon of the spring equinox: 14th of Nisan in the Jewish calendar. It did not matter to them what day of the week it fell.

All the other Churches, led by Rome, celebrated Easter on the Sunday following 14th of Nisan.

At the Ecumenical Council of Nicaea in 325, all the Churches agreed that the Lord's resurrection should be observed on this latter date. This remained the standard in both East and West for the next 12 centuries.

The Christian world followed the Julian calendar, established by Julius Caesar in 46 B.C. To correct certain inaccuracies of this calendar, Pope Gregory XIII had it reformed in 1582. He took into account new criteria for calculating Easter day — the first Sunday after the full moon of the spring equinox, that is, between March 22 and April 25.

Claiming fidelity to Nicaea, the patriarch of Constantinople, Jeremiah II, refused to adopt the Gregorian calendar because it was promulgated without the consent of the Greek Church. This caused a discrepancy of several days between the Western (Gregorian) calendar and the Eastern (Julian) one.

The Second Vatican Council expressed willingness to come to an agreement with the churches separated from Rome on a common date for Easter in the appendix of Sacrosanctum Concilium, the dogmatic constitution on the sacred liturgy. The feast of Easter would be assigned to a particular Sunday, “provided that those whom it may concern, especially the brethren who are not in communion with the Apostolic See, give their assent.”

The Catechism of the Catholic Church (No. 1170) and John Paul have expressed the same desire. “I pray to the risen Lord,” the Pope said on Easter Sunday, “that all of us baptized will soon be able to relive every year together on the same day of this fundamental feast of our faith.”

In effect, a common date to celebrate the “feast of feasts” and the “solemnity of solemnities” (Catechism, No. 1169) would visibly express and forcefully promote Christian unity. “Christ calls all his disciples to unity,” the Holy Father wrote in his 1995 encyclical Ut Unum Sint (That They May Be One).

It would also mirror the eternal Easter we are all called to enjoy together without divisions and discrepancies. As St. Augustine said, we are “Easter people and alleluia is our song.”

The enthusiastic and prayerful voices of the 15 or so Orthodox bearded priests who sang to the 100,000 faithful attending the Pope's Easter Mass at St. Peter's Square echoed St. Augustine's thought.

There was no need to understand the lyrics. The Greek melody and words were enough to inspire a dialogue with our Chris-tos (Christ), who is our Pascha (Passover).

How joyful and effective for the New Evangelization would it be to see all the members of the militant Church singing together at Eastertide around the Vicar of Christ in preparation for the triumphant Church's eternal song to the risen Lord!

Legionary Father Alfonso Aguilar teaches philosophy at Regina Apostolorum Pontifical University in Rome and can be reached at [email protected].